Remove all remaining sessiond kernel command
[lttng-tools.git] / ltt-sessiond / main.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; only version 2
7 * of the License.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18
19 #define _GNU_SOURCE
20 #include <fcntl.h>
21 #include <getopt.h>
22 #include <grp.h>
23 #include <limits.h>
24 #include <poll.h>
25 #include <pthread.h>
26 #include <semaphore.h>
27 #include <signal.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <sys/ipc.h>
32 #include <sys/mount.h>
33 #include <sys/shm.h>
34 #include <sys/socket.h>
35 #include <sys/stat.h>
36 #include <sys/types.h>
37 #include <sys/time.h>
38 #include <sys/resource.h>
39 #include <unistd.h>
40
41 #include <urcu/list.h> /* URCU list library (-lurcu) */
42 #include <lttng/lttng.h>
43
44 #include "context.h"
45 #include "liblttsessiondcomm.h"
46 #include "ltt-sessiond.h"
47 #include "lttngerr.h"
48 #include "kernel-ctl.h"
49 #include "ust-ctl.h"
50 #include "session.h"
51 #include "traceable-app.h"
52 #include "lttng-kconsumerd.h"
53 #include "utils.h"
54
55 /* Const values */
56 const char default_home_dir[] = DEFAULT_HOME_DIR;
57 const char default_tracing_group[] = LTTNG_DEFAULT_TRACING_GROUP;
58 const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
59 const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
60
61 /* Variables */
62 int opt_verbose; /* Not static for lttngerr.h */
63 int opt_quiet; /* Not static for lttngerr.h */
64
65 const char *progname;
66 const char *opt_tracing_group;
67 static int opt_sig_parent;
68 static int opt_daemon;
69 static int is_root; /* Set to 1 if the daemon is running as root */
70 static pid_t ppid; /* Parent PID for --sig-parent option */
71 static pid_t kconsumerd_pid;
72 static struct pollfd *kernel_pollfd;
73
74 static char apps_unix_sock_path[PATH_MAX]; /* Global application Unix socket path */
75 static char client_unix_sock_path[PATH_MAX]; /* Global client Unix socket path */
76 static char kconsumerd_err_unix_sock_path[PATH_MAX]; /* kconsumerd error Unix socket path */
77 static char kconsumerd_cmd_unix_sock_path[PATH_MAX]; /* kconsumerd command Unix socket path */
78
79 /* Sockets and FDs */
80 static int client_sock;
81 static int apps_sock;
82 static int kconsumerd_err_sock;
83 static int kconsumerd_cmd_sock;
84 static int kernel_tracer_fd;
85 static int kernel_poll_pipe[2];
86
87 /*
88 * Quit pipe for all threads. This permits a single cancellation point
89 * for all threads when receiving an event on the pipe.
90 */
91 static int thread_quit_pipe[2];
92
93 /* Pthread, Mutexes and Semaphores */
94 static pthread_t kconsumerd_thread;
95 static pthread_t apps_thread;
96 static pthread_t client_thread;
97 static pthread_t kernel_thread;
98 static sem_t kconsumerd_sem;
99
100 static pthread_mutex_t kconsumerd_pid_mutex; /* Mutex to control kconsumerd pid assignation */
101
102 /*
103 * Pointer initialized before thread creation.
104 *
105 * This points to the tracing session list containing the session count and a
106 * mutex lock. The lock MUST be taken if you iterate over the list. The lock
107 * MUST NOT be taken if you call a public function in session.c.
108 *
109 * The lock is nested inside the structure: session_list_ptr->lock. Please use
110 * lock_session_list and unlock_session_list for lock acquisition.
111 */
112 static struct ltt_session_list *session_list_ptr;
113
114 /*
115 * Init quit pipe.
116 *
117 * Return -1 on error or 0 if all pipes are created.
118 */
119 static int init_thread_quit_pipe(void)
120 {
121 int ret;
122
123 ret = pipe2(thread_quit_pipe, O_CLOEXEC);
124 if (ret < 0) {
125 perror("thread quit pipe");
126 goto error;
127 }
128
129 error:
130 return ret;
131 }
132
133 /*
134 * Complete teardown of a kernel session. This free all data structure related
135 * to a kernel session and update counter.
136 */
137 static void teardown_kernel_session(struct ltt_session *session)
138 {
139 if (session->kernel_session != NULL) {
140 DBG("Tearing down kernel session");
141 trace_destroy_kernel_session(session->kernel_session);
142 /* Extra precaution */
143 session->kernel_session = NULL;
144 }
145 }
146
147 /*
148 * Cleanup the daemon
149 */
150 static void cleanup()
151 {
152 int ret;
153 char *cmd;
154 struct ltt_session *sess, *stmp;
155
156 DBG("Cleaning up");
157
158 /* <fun> */
159 MSG("\n%c[%d;%dm*** assert failed *** ==> %c[%dm%c[%d;%dm"
160 "Matthew, BEET driven development works!%c[%dm",
161 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
162 /* </fun> */
163
164 /* Stopping all threads */
165 DBG("Terminating all threads");
166 close(thread_quit_pipe[0]);
167 close(thread_quit_pipe[1]);
168
169 DBG("Removing %s directory", LTTNG_RUNDIR);
170 ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
171 if (ret < 0) {
172 ERR("asprintf failed. Something is really wrong!");
173 }
174
175 /* Remove lttng run directory */
176 ret = system(cmd);
177 if (ret < 0) {
178 ERR("Unable to clean " LTTNG_RUNDIR);
179 }
180
181 DBG("Cleaning up all session");
182
183 /* Destroy session list mutex */
184 if (session_list_ptr != NULL) {
185 pthread_mutex_destroy(&session_list_ptr->lock);
186
187 /* Cleanup ALL session */
188 cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
189 teardown_kernel_session(sess);
190 // TODO complete session cleanup (including UST)
191 }
192 }
193
194 pthread_mutex_destroy(&kconsumerd_pid_mutex);
195
196 DBG("Closing kernel fd");
197 close(kernel_tracer_fd);
198 }
199
200 /*
201 * Send data on a unix socket using the liblttsessiondcomm API.
202 *
203 * Return lttcomm error code.
204 */
205 static int send_unix_sock(int sock, void *buf, size_t len)
206 {
207 /* Check valid length */
208 if (len <= 0) {
209 return -1;
210 }
211
212 return lttcomm_send_unix_sock(sock, buf, len);
213 }
214
215 /*
216 * Free memory of a command context structure.
217 */
218 static void clean_command_ctx(struct command_ctx **cmd_ctx)
219 {
220 DBG("Clean command context structure");
221 if (*cmd_ctx) {
222 if ((*cmd_ctx)->llm) {
223 free((*cmd_ctx)->llm);
224 }
225 if ((*cmd_ctx)->lsm) {
226 free((*cmd_ctx)->lsm);
227 }
228 free(*cmd_ctx);
229 *cmd_ctx = NULL;
230 }
231 }
232
233 /*
234 * Send all stream fds of kernel channel to the consumer.
235 */
236 static int send_kconsumerd_channel_fds(int sock, struct ltt_kernel_channel *channel)
237 {
238 int ret;
239 size_t nb_fd;
240 struct ltt_kernel_stream *stream;
241 struct lttcomm_kconsumerd_header lkh;
242 struct lttcomm_kconsumerd_msg lkm;
243
244 DBG("Sending fds of channel %s to kernel consumer", channel->channel->name);
245
246 nb_fd = channel->stream_count;
247
248 /* Setup header */
249 lkh.payload_size = nb_fd * sizeof(struct lttcomm_kconsumerd_msg);
250 lkh.cmd_type = ADD_STREAM;
251
252 DBG("Sending kconsumerd header");
253
254 ret = lttcomm_send_unix_sock(sock, &lkh, sizeof(struct lttcomm_kconsumerd_header));
255 if (ret < 0) {
256 perror("send kconsumerd header");
257 goto error;
258 }
259
260 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
261 if (stream->fd != 0) {
262 lkm.fd = stream->fd;
263 lkm.state = stream->state;
264 lkm.max_sb_size = channel->channel->attr.subbuf_size;
265 strncpy(lkm.path_name, stream->pathname, PATH_MAX);
266
267 DBG("Sending fd %d to kconsumerd", lkm.fd);
268
269 ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
270 if (ret < 0) {
271 perror("send kconsumerd fd");
272 goto error;
273 }
274 }
275 }
276
277 DBG("Kconsumerd channel fds sent");
278
279 return 0;
280
281 error:
282 return ret;
283 }
284
285 /*
286 * Send all stream fds of the kernel session to the consumer.
287 */
288 static int send_kconsumerd_fds(int sock, struct ltt_kernel_session *session)
289 {
290 int ret;
291 struct ltt_kernel_channel *chan;
292 struct lttcomm_kconsumerd_header lkh;
293 struct lttcomm_kconsumerd_msg lkm;
294
295 /* Setup header */
296 lkh.payload_size = sizeof(struct lttcomm_kconsumerd_msg);
297 lkh.cmd_type = ADD_STREAM;
298
299 DBG("Sending kconsumerd header for metadata");
300
301 ret = lttcomm_send_unix_sock(sock, &lkh, sizeof(struct lttcomm_kconsumerd_header));
302 if (ret < 0) {
303 perror("send kconsumerd header");
304 goto error;
305 }
306
307 DBG("Sending metadata stream fd");
308
309 if (session->metadata_stream_fd != 0) {
310 /* Send metadata stream fd first */
311 lkm.fd = session->metadata_stream_fd;
312 lkm.state = ACTIVE_FD;
313 lkm.max_sb_size = session->metadata->conf->attr.subbuf_size;
314 strncpy(lkm.path_name, session->metadata->pathname, PATH_MAX);
315
316 ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
317 if (ret < 0) {
318 perror("send kconsumerd fd");
319 goto error;
320 }
321 }
322
323 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
324 ret = send_kconsumerd_channel_fds(sock, chan);
325 if (ret < 0) {
326 goto error;
327 }
328 }
329
330 DBG("Kconsumerd fds (metadata and channel streams) sent");
331
332 return 0;
333
334 error:
335 return ret;
336 }
337
338 #ifdef DISABLED
339 /*
340 * Return a socket connected to the libust communication socket of the
341 * application identified by the pid.
342 *
343 * If the pid is not found in the traceable list, return -1 to indicate error.
344 */
345 static int ust_connect_app(pid_t pid)
346 {
347 int sock;
348 struct ltt_traceable_app *lta;
349
350 DBG("Connect to application pid %d", pid);
351
352 lta = find_app_by_pid(pid);
353 if (lta == NULL) {
354 /* App not found */
355 DBG("Application pid %d not found", pid);
356 return -1;
357 }
358
359 sock = ustctl_connect_pid(lta->pid);
360 if (sock < 0) {
361 ERR("Fail connecting to the PID %d", pid);
362 }
363
364 return sock;
365 }
366 #endif /* DISABLED */
367
368 /*
369 * Notify apps by writing 42 to a named pipe using name. Every applications
370 * waiting for a ltt-sessiond will be notified and re-register automatically to
371 * the session daemon.
372 *
373 * Return open or write error value.
374 */
375 static int notify_apps(const char *name)
376 {
377 int fd;
378 int ret = -1;
379
380 DBG("Notify the global application pipe");
381
382 /* Try opening the global pipe */
383 fd = open(name, O_WRONLY);
384 if (fd < 0) {
385 goto error;
386 }
387
388 /* Notify by writing on the pipe */
389 ret = write(fd, "42", 2);
390 if (ret < 0) {
391 perror("write");
392 }
393
394 error:
395 return ret;
396 }
397
398 /*
399 * Setup the outgoing data buffer for the response (llm) by allocating the
400 * right amount of memory and copying the original information from the lsm
401 * structure.
402 *
403 * Return total size of the buffer pointed by buf.
404 */
405 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
406 {
407 int ret, buf_size;
408
409 buf_size = size;
410
411 cmd_ctx->llm = malloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
412 if (cmd_ctx->llm == NULL) {
413 perror("malloc");
414 ret = -ENOMEM;
415 goto error;
416 }
417
418 /* Copy common data */
419 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
420 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
421
422 cmd_ctx->llm->data_size = size;
423 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
424
425 return buf_size;
426
427 error:
428 return ret;
429 }
430
431 /*
432 * Update the kernel pollfd set of all channel fd available over all tracing
433 * session. Add the wakeup pipe at the end of the set.
434 */
435 static int update_kernel_pollfd(void)
436 {
437 int i = 0;
438 /*
439 * The wakup pipe and the quit pipe are needed so the number of fds starts
440 * at 2 for those pipes.
441 */
442 unsigned int nb_fd = 2;
443 struct ltt_session *session;
444 struct ltt_kernel_channel *channel;
445
446 DBG("Updating kernel_pollfd");
447
448 /* Get the number of channel of all kernel session */
449 lock_session_list();
450 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
451 lock_session(session);
452 if (session->kernel_session == NULL) {
453 unlock_session(session);
454 continue;
455 }
456 nb_fd += session->kernel_session->channel_count;
457 unlock_session(session);
458 }
459
460 DBG("Resizing kernel_pollfd to size %d", nb_fd);
461
462 kernel_pollfd = realloc(kernel_pollfd, nb_fd * sizeof(struct pollfd));
463 if (kernel_pollfd == NULL) {
464 perror("malloc kernel_pollfd");
465 goto error;
466 }
467
468 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
469 lock_session(session);
470 if (session->kernel_session == NULL) {
471 unlock_session(session);
472 continue;
473 }
474 if (i >= nb_fd) {
475 ERR("To much channel for kernel_pollfd size");
476 unlock_session(session);
477 break;
478 }
479 cds_list_for_each_entry(channel, &session->kernel_session->channel_list.head, list) {
480 kernel_pollfd[i].fd = channel->fd;
481 kernel_pollfd[i].events = POLLIN | POLLRDNORM;
482 i++;
483 }
484 unlock_session(session);
485 }
486 unlock_session_list();
487
488 /* Adding wake up pipe */
489 kernel_pollfd[nb_fd - 2].fd = kernel_poll_pipe[0];
490 kernel_pollfd[nb_fd - 2].events = POLLIN;
491
492 /* Adding the quit pipe */
493 kernel_pollfd[nb_fd - 1].fd = thread_quit_pipe[0];
494
495 return nb_fd;
496
497 error:
498 unlock_session_list();
499 return -1;
500 }
501
502 /*
503 * Find the channel fd from 'fd' over all tracing session. When found, check
504 * for new channel stream and send those stream fds to the kernel consumer.
505 *
506 * Useful for CPU hotplug feature.
507 */
508 static int update_kernel_stream(int fd)
509 {
510 int ret = 0;
511 struct ltt_session *session;
512 struct ltt_kernel_channel *channel;
513
514 DBG("Updating kernel streams for channel fd %d", fd);
515
516 lock_session_list();
517 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
518 lock_session(session);
519 if (session->kernel_session == NULL) {
520 unlock_session(session);
521 continue;
522 }
523 cds_list_for_each_entry(channel, &session->kernel_session->channel_list.head, list) {
524 if (channel->fd == fd) {
525 DBG("Channel found, updating kernel streams");
526 ret = kernel_open_channel_stream(channel);
527 if (ret < 0) {
528 goto end;
529 }
530 /*
531 * Have we already sent fds to the consumer? If yes, it means that
532 * tracing is started so it is safe to send our updated stream fds.
533 */
534 if (session->kernel_session->kconsumer_fds_sent == 1) {
535 ret = send_kconsumerd_channel_fds(kconsumerd_cmd_sock, channel);
536 if (ret < 0) {
537 goto end;
538 }
539 }
540 goto end;
541 }
542 }
543 unlock_session(session);
544 }
545
546 end:
547 unlock_session_list();
548 if (session) {
549 unlock_session(session);
550 }
551 return ret;
552 }
553
554 /*
555 * This thread manage event coming from the kernel.
556 *
557 * Features supported in this thread:
558 * -) CPU Hotplug
559 */
560 static void *thread_manage_kernel(void *data)
561 {
562 int ret, i, nb_fd = 0;
563 char tmp;
564 int update_poll_flag = 1;
565
566 DBG("Thread manage kernel started");
567
568 while (1) {
569 if (update_poll_flag == 1) {
570 nb_fd = update_kernel_pollfd();
571 if (nb_fd < 0) {
572 goto error;
573 }
574 update_poll_flag = 0;
575 }
576
577 DBG("Polling on %d fds", nb_fd);
578
579 /* Poll infinite value of time */
580 ret = poll(kernel_pollfd, nb_fd, -1);
581 if (ret < 0) {
582 perror("poll kernel thread");
583 goto error;
584 } else if (ret == 0) {
585 /* Should not happen since timeout is infinite */
586 continue;
587 }
588
589 /* Thread quit pipe has been closed. Killing thread. */
590 if (kernel_pollfd[nb_fd - 1].revents == POLLNVAL) {
591 goto error;
592 }
593
594 DBG("Kernel poll event triggered");
595
596 /*
597 * Check if the wake up pipe was triggered. If so, the kernel_pollfd
598 * must be updated.
599 */
600 switch (kernel_pollfd[nb_fd - 2].revents) {
601 case POLLIN:
602 ret = read(kernel_poll_pipe[0], &tmp, 1);
603 update_poll_flag = 1;
604 continue;
605 case POLLERR:
606 goto error;
607 default:
608 break;
609 }
610
611 for (i = 0; i < nb_fd; i++) {
612 switch (kernel_pollfd[i].revents) {
613 /*
614 * New CPU detected by the kernel. Adding kernel stream to kernel
615 * session and updating the kernel consumer
616 */
617 case POLLIN | POLLRDNORM:
618 ret = update_kernel_stream(kernel_pollfd[i].fd);
619 if (ret < 0) {
620 continue;
621 }
622 break;
623 }
624 }
625 }
626
627 error:
628 DBG("Kernel thread dying");
629 if (kernel_pollfd) {
630 free(kernel_pollfd);
631 }
632
633 close(kernel_poll_pipe[0]);
634 close(kernel_poll_pipe[1]);
635 return NULL;
636 }
637
638 /*
639 * This thread manage the kconsumerd error sent back to the session daemon.
640 */
641 static void *thread_manage_kconsumerd(void *data)
642 {
643 int sock = 0, ret;
644 enum lttcomm_return_code code;
645 struct pollfd pollfd[2];
646
647 DBG("[thread] Manage kconsumerd started");
648
649 ret = lttcomm_listen_unix_sock(kconsumerd_err_sock);
650 if (ret < 0) {
651 goto error;
652 }
653
654 /* First fd is always the quit pipe */
655 pollfd[0].fd = thread_quit_pipe[0];
656
657 /* Apps socket */
658 pollfd[1].fd = kconsumerd_err_sock;
659 pollfd[1].events = POLLIN;
660
661 /* Inifinite blocking call, waiting for transmission */
662 ret = poll(pollfd, 2, -1);
663 if (ret < 0) {
664 perror("poll kconsumerd thread");
665 goto error;
666 }
667
668 /* Thread quit pipe has been closed. Killing thread. */
669 if (pollfd[0].revents == POLLNVAL) {
670 goto error;
671 } else if (pollfd[1].revents == POLLERR) {
672 ERR("Kconsumerd err socket poll error");
673 goto error;
674 }
675
676 sock = lttcomm_accept_unix_sock(kconsumerd_err_sock);
677 if (sock < 0) {
678 goto error;
679 }
680
681 /* Getting status code from kconsumerd */
682 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
683 if (ret <= 0) {
684 goto error;
685 }
686
687 if (code == KCONSUMERD_COMMAND_SOCK_READY) {
688 kconsumerd_cmd_sock = lttcomm_connect_unix_sock(kconsumerd_cmd_unix_sock_path);
689 if (kconsumerd_cmd_sock < 0) {
690 sem_post(&kconsumerd_sem);
691 perror("kconsumerd connect");
692 goto error;
693 }
694 /* Signal condition to tell that the kconsumerd is ready */
695 sem_post(&kconsumerd_sem);
696 DBG("Kconsumerd command socket ready");
697 } else {
698 DBG("Kconsumerd error when waiting for SOCK_READY : %s",
699 lttcomm_get_readable_code(-code));
700 goto error;
701 }
702
703 /* Wait for any kconsumerd error */
704 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
705 if (ret <= 0) {
706 ERR("Kconsumerd closed the command socket");
707 goto error;
708 }
709
710 ERR("Kconsumerd return code : %s", lttcomm_get_readable_code(-code));
711
712 error:
713 DBG("Kconsumerd thread dying");
714 if (kconsumerd_err_sock) {
715 close(kconsumerd_err_sock);
716 }
717 if (kconsumerd_cmd_sock) {
718 close(kconsumerd_cmd_sock);
719 }
720 if (sock) {
721 close(sock);
722 }
723
724 unlink(kconsumerd_err_unix_sock_path);
725 unlink(kconsumerd_cmd_unix_sock_path);
726
727 kconsumerd_pid = 0;
728 return NULL;
729 }
730
731 /*
732 * This thread manage the application socket communication
733 */
734 static void *thread_manage_apps(void *data)
735 {
736 int sock = 0, ret;
737 struct pollfd pollfd[2];
738
739 /* TODO: Something more elegant is needed but fine for now */
740 /* FIXME: change all types to either uint8_t, uint32_t, uint64_t
741 * for 32-bit vs 64-bit compat processes. */
742 /* replicate in ust with version number */
743 struct {
744 int reg; /* 1:register, 0:unregister */
745 pid_t pid;
746 uid_t uid;
747 } reg_msg;
748
749 DBG("[thread] Manage apps started");
750
751 ret = lttcomm_listen_unix_sock(apps_sock);
752 if (ret < 0) {
753 goto error;
754 }
755
756 /* First fd is always the quit pipe */
757 pollfd[0].fd = thread_quit_pipe[0];
758
759 /* Apps socket */
760 pollfd[1].fd = apps_sock;
761 pollfd[1].events = POLLIN;
762
763 /* Notify all applications to register */
764 notify_apps(default_global_apps_pipe);
765
766 while (1) {
767 DBG("Accepting application registration");
768
769 /* Inifinite blocking call, waiting for transmission */
770 ret = poll(pollfd, 2, -1);
771 if (ret < 0) {
772 perror("poll apps thread");
773 goto error;
774 }
775
776 /* Thread quit pipe has been closed. Killing thread. */
777 if (pollfd[0].revents == POLLNVAL) {
778 goto error;
779 } else if (pollfd[1].revents == POLLERR) {
780 ERR("Apps socket poll error");
781 goto error;
782 }
783
784 sock = lttcomm_accept_unix_sock(apps_sock);
785 if (sock < 0) {
786 goto error;
787 }
788
789 /*
790 * Basic recv here to handle the very simple data
791 * that the libust send to register (reg_msg).
792 */
793 ret = recv(sock, &reg_msg, sizeof(reg_msg), 0);
794 if (ret < 0) {
795 perror("recv");
796 continue;
797 }
798
799 /* Add application to the global traceable list */
800 if (reg_msg.reg == 1) {
801 /* Registering */
802 ret = register_traceable_app(reg_msg.pid, reg_msg.uid);
803 if (ret < 0) {
804 /* register_traceable_app only return an error with
805 * ENOMEM. At this point, we better stop everything.
806 */
807 goto error;
808 }
809 } else {
810 /* Unregistering */
811 unregister_traceable_app(reg_msg.pid);
812 }
813 }
814
815 error:
816 DBG("Apps thread dying");
817 if (apps_sock) {
818 close(apps_sock);
819 }
820 if (sock) {
821 close(sock);
822 }
823
824 unlink(apps_unix_sock_path);
825 return NULL;
826 }
827
828 /*
829 * Start the thread_manage_kconsumerd. This must be done after a kconsumerd
830 * exec or it will fails.
831 */
832 static int spawn_kconsumerd_thread(void)
833 {
834 int ret;
835
836 /* Setup semaphore */
837 sem_init(&kconsumerd_sem, 0, 0);
838
839 ret = pthread_create(&kconsumerd_thread, NULL, thread_manage_kconsumerd, (void *) NULL);
840 if (ret != 0) {
841 perror("pthread_create kconsumerd");
842 goto error;
843 }
844
845 /* Wait for the kconsumerd thread to be ready */
846 sem_wait(&kconsumerd_sem);
847
848 if (kconsumerd_pid == 0) {
849 ERR("Kconsumerd did not start");
850 goto error;
851 }
852
853 return 0;
854
855 error:
856 ret = LTTCOMM_KERN_CONSUMER_FAIL;
857 return ret;
858 }
859
860 /*
861 * Fork and exec a kernel consumer daemon (kconsumerd).
862 *
863 * Return pid if successful else -1.
864 */
865 static pid_t spawn_kconsumerd(void)
866 {
867 int ret;
868 pid_t pid;
869 const char *verbosity;
870
871 DBG("Spawning kconsumerd");
872
873 pid = fork();
874 if (pid == 0) {
875 /*
876 * Exec kconsumerd.
877 */
878 if (opt_verbose > 1) {
879 verbosity = "--verbose";
880 } else {
881 verbosity = "--quiet";
882 }
883 execl(INSTALL_BIN_PATH "/ltt-kconsumerd", "ltt-kconsumerd", verbosity, NULL);
884 if (errno != 0) {
885 perror("kernel start consumer exec");
886 }
887 exit(EXIT_FAILURE);
888 } else if (pid > 0) {
889 ret = pid;
890 goto error;
891 } else {
892 perror("kernel start consumer fork");
893 ret = -errno;
894 goto error;
895 }
896
897 error:
898 return ret;
899 }
900
901 /*
902 * Spawn the kconsumerd daemon and session daemon thread.
903 */
904 static int start_kconsumerd(void)
905 {
906 int ret;
907
908 pthread_mutex_lock(&kconsumerd_pid_mutex);
909 if (kconsumerd_pid != 0) {
910 pthread_mutex_unlock(&kconsumerd_pid_mutex);
911 goto end;
912 }
913
914 ret = spawn_kconsumerd();
915 if (ret < 0) {
916 ERR("Spawning kconsumerd failed");
917 ret = LTTCOMM_KERN_CONSUMER_FAIL;
918 pthread_mutex_unlock(&kconsumerd_pid_mutex);
919 goto error;
920 }
921
922 /* Setting up the global kconsumerd_pid */
923 kconsumerd_pid = ret;
924 pthread_mutex_unlock(&kconsumerd_pid_mutex);
925
926 DBG("Kconsumerd pid %d", ret);
927
928 DBG("Spawning kconsumerd thread");
929 ret = spawn_kconsumerd_thread();
930 if (ret < 0) {
931 ERR("Fatal error spawning kconsumerd thread");
932 goto error;
933 }
934
935 end:
936 return 0;
937
938 error:
939 return ret;
940 }
941
942 /*
943 * modprobe_kernel_modules
944 */
945 static int modprobe_kernel_modules(void)
946 {
947 int ret = 0, i = 0;
948 char modprobe[256];
949
950 while (kernel_modules_list[i] != NULL) {
951 ret = snprintf(modprobe, sizeof(modprobe), "/sbin/modprobe %s",
952 kernel_modules_list[i]);
953 if (ret < 0) {
954 perror("snprintf modprobe");
955 goto error;
956 }
957 ret = system(modprobe);
958 if (ret < 0) {
959 ERR("Unable to load module %s", kernel_modules_list[i]);
960 }
961 DBG("Modprobe successfully %s", kernel_modules_list[i]);
962 i++;
963 }
964
965 error:
966 return ret;
967 }
968
969 /*
970 * mount_debugfs
971 */
972 static int mount_debugfs(char *path)
973 {
974 int ret;
975 char *type = "debugfs";
976
977 ret = mkdir_recursive(path, S_IRWXU | S_IRWXG);
978 if (ret < 0) {
979 goto error;
980 }
981
982 ret = mount(type, path, type, 0, NULL);
983 if (ret < 0) {
984 perror("mount debugfs");
985 goto error;
986 }
987
988 DBG("Mounted debugfs successfully at %s", path);
989
990 error:
991 return ret;
992 }
993
994 /*
995 * Setup necessary data for kernel tracer action.
996 */
997 static void init_kernel_tracer(void)
998 {
999 int ret;
1000 char *proc_mounts = "/proc/mounts";
1001 char line[256];
1002 char *debugfs_path = NULL, *lttng_path;
1003 FILE *fp;
1004
1005 /* Detect debugfs */
1006 fp = fopen(proc_mounts, "r");
1007 if (fp == NULL) {
1008 ERR("Unable to probe %s", proc_mounts);
1009 goto error;
1010 }
1011
1012 while (fgets(line, sizeof(line), fp) != NULL) {
1013 if (strstr(line, "debugfs") != NULL) {
1014 /* Remove first string */
1015 strtok(line, " ");
1016 /* Dup string here so we can reuse line later on */
1017 debugfs_path = strdup(strtok(NULL, " "));
1018 DBG("Got debugfs path : %s", debugfs_path);
1019 break;
1020 }
1021 }
1022
1023 fclose(fp);
1024
1025 /* Mount debugfs if needded */
1026 if (debugfs_path == NULL) {
1027 ret = asprintf(&debugfs_path, "/mnt/debugfs");
1028 if (ret < 0) {
1029 perror("asprintf debugfs path");
1030 goto error;
1031 }
1032 ret = mount_debugfs(debugfs_path);
1033 if (ret < 0) {
1034 goto error;
1035 }
1036 }
1037
1038 /* Modprobe lttng kernel modules */
1039 ret = modprobe_kernel_modules();
1040 if (ret < 0) {
1041 goto error;
1042 }
1043
1044 /* Setup lttng kernel path */
1045 ret = asprintf(&lttng_path, "%s/lttng", debugfs_path);
1046 if (ret < 0) {
1047 perror("asprintf lttng path");
1048 goto error;
1049 }
1050
1051 /* Open debugfs lttng */
1052 kernel_tracer_fd = open(lttng_path, O_RDWR);
1053 if (kernel_tracer_fd < 0) {
1054 DBG("Failed to open %s", lttng_path);
1055 goto error;
1056 }
1057
1058 free(lttng_path);
1059 free(debugfs_path);
1060 DBG("Kernel tracer fd %d", kernel_tracer_fd);
1061 return;
1062
1063 error:
1064 if (lttng_path) {
1065 free(lttng_path);
1066 }
1067 if (debugfs_path) {
1068 free(debugfs_path);
1069 }
1070 WARN("No kernel tracer available");
1071 kernel_tracer_fd = 0;
1072 return;
1073 }
1074
1075 /*
1076 * Start tracing by creating trace directory and sending FDs to the kernel
1077 * consumer.
1078 */
1079 static int start_kernel_trace(struct ltt_kernel_session *session)
1080 {
1081 int ret = 0;
1082
1083 if (session->kconsumer_fds_sent == 0) {
1084 ret = send_kconsumerd_fds(kconsumerd_cmd_sock, session);
1085 if (ret < 0) {
1086 ERR("Send kconsumerd fds failed");
1087 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1088 goto error;
1089 }
1090
1091 session->kconsumer_fds_sent = 1;
1092 }
1093
1094 error:
1095 return ret;
1096 }
1097
1098 /*
1099 * Notify kernel thread to update it's pollfd.
1100 */
1101 static int notify_kernel_pollfd(void)
1102 {
1103 int ret;
1104
1105 /* Inform kernel thread of the new kernel channel */
1106 ret = write(kernel_poll_pipe[1], "!", 1);
1107 if (ret < 0) {
1108 perror("write kernel poll pipe");
1109 }
1110
1111 return ret;
1112 }
1113
1114 /*
1115 * Allocate a channel structure and fill it.
1116 */
1117 static struct lttng_channel *init_default_channel(char *name)
1118 {
1119 struct lttng_channel *chan;
1120
1121 chan = malloc(sizeof(struct lttng_channel));
1122 if (chan == NULL) {
1123 perror("init channel malloc");
1124 goto error;
1125 }
1126
1127 if (snprintf(chan->name, NAME_MAX, "%s", name) < 0) {
1128 perror("snprintf channel name");
1129 return NULL;
1130 }
1131
1132 chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
1133 chan->attr.subbuf_size = DEFAULT_CHANNEL_SUBBUF_SIZE;
1134 chan->attr.num_subbuf = DEFAULT_CHANNEL_SUBBUF_NUM;
1135 chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
1136 chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
1137 chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
1138
1139 error:
1140 return chan;
1141 }
1142
1143 /*
1144 * Create a kernel tracer session then create the default channel.
1145 */
1146 static int create_kernel_session(struct ltt_session *session)
1147 {
1148 int ret;
1149
1150 DBG("Creating kernel session");
1151
1152 ret = kernel_create_session(session, kernel_tracer_fd);
1153 if (ret < 0) {
1154 ret = LTTCOMM_KERN_SESS_FAIL;
1155 goto error;
1156 }
1157
1158 ret = mkdir_recursive(session->path, S_IRWXU | S_IRWXG );
1159 if (ret < 0) {
1160 if (ret != EEXIST) {
1161 ERR("Trace directory creation error");
1162 goto error;
1163 }
1164 }
1165
1166 error:
1167 return ret;
1168 }
1169
1170 /*
1171 * Using the session list, filled a lttng_session array to send back to the
1172 * client for session listing.
1173 *
1174 * The session list lock MUST be acquired before calling this function. Use
1175 * lock_session_list() and unlock_session_list().
1176 */
1177 static void list_lttng_sessions(struct lttng_session *sessions)
1178 {
1179 int i = 0;
1180 struct ltt_session *session;
1181
1182 DBG("Getting all available session");
1183 /*
1184 * Iterate over session list and append data after the control struct in
1185 * the buffer.
1186 */
1187 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1188 strncpy(sessions[i].path, session->path, PATH_MAX);
1189 strncpy(sessions[i].name, session->name, NAME_MAX);
1190 i++;
1191 }
1192 }
1193
1194 /*
1195 * Fill lttng_channel array of all channels.
1196 */
1197 static void list_lttng_channels(struct ltt_session *session,
1198 struct lttng_channel *channels)
1199 {
1200 int i = 0;
1201 struct ltt_kernel_channel *kchan;
1202
1203 DBG("Listing channels for session %s", session->name);
1204
1205 /* Kernel channels */
1206 if (session->kernel_session != NULL) {
1207 cds_list_for_each_entry(kchan, &session->kernel_session->channel_list.head, list) {
1208 /* Copy lttng_channel struct to array */
1209 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
1210 channels[i].enabled = kchan->enabled;
1211 i++;
1212 }
1213 }
1214
1215 /* TODO: Missing UST listing */
1216 }
1217
1218 /*
1219 * Fill lttng_event array of all events in the channel.
1220 */
1221 static void list_lttng_events(struct ltt_kernel_channel *kchan,
1222 struct lttng_event *events)
1223 {
1224 /*
1225 * TODO: This is ONLY kernel. Need UST support.
1226 */
1227 int i = 0;
1228 struct ltt_kernel_event *event;
1229
1230 DBG("Listing events for channel %s", kchan->channel->name);
1231
1232 /* Kernel channels */
1233 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
1234 strncpy(events[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
1235 events[i].enabled = event->enabled;
1236 switch (event->event->instrumentation) {
1237 case LTTNG_KERNEL_TRACEPOINT:
1238 events[i].type = LTTNG_EVENT_TRACEPOINT;
1239 break;
1240 case LTTNG_KERNEL_KPROBE:
1241 case LTTNG_KERNEL_KRETPROBE:
1242 events[i].type = LTTNG_EVENT_PROBE;
1243 memcpy(&events[i].attr.probe, &event->event->u.kprobe,
1244 sizeof(struct lttng_kernel_kprobe));
1245 break;
1246 case LTTNG_KERNEL_FUNCTION:
1247 events[i].type = LTTNG_EVENT_FUNCTION;
1248 memcpy(&events[i].attr.ftrace, &event->event->u.ftrace,
1249 sizeof(struct lttng_kernel_function));
1250 break;
1251 }
1252 i++;
1253 }
1254 }
1255
1256 /*
1257 * Process the command requested by the lttng client within the command
1258 * context structure. This function make sure that the return structure (llm)
1259 * is set and ready for transmission before returning.
1260 *
1261 * Return any error encountered or 0 for success.
1262 */
1263 static int process_client_msg(struct command_ctx *cmd_ctx)
1264 {
1265 int ret = LTTCOMM_OK;
1266
1267 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
1268
1269 /* Listing commands don't need a session */
1270 switch (cmd_ctx->lsm->cmd_type) {
1271 case LTTNG_CREATE_SESSION:
1272 case LTTNG_LIST_SESSIONS:
1273 case LTTNG_LIST_TRACEPOINTS:
1274 break;
1275 default:
1276 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
1277 cmd_ctx->session = find_session_by_name(cmd_ctx->lsm->session.name);
1278 if (cmd_ctx->session == NULL) {
1279 /* If session name not found */
1280 if (cmd_ctx->lsm->session.name != NULL) {
1281 ret = LTTCOMM_SESS_NOT_FOUND;
1282 } else { /* If no session name specified */
1283 ret = LTTCOMM_SELECT_SESS;
1284 }
1285 goto error;
1286 } else {
1287 /* Acquire lock for the session */
1288 lock_session(cmd_ctx->session);
1289 }
1290 break;
1291 }
1292
1293 /*
1294 * Check domain type for specifif "pre-action".
1295 */
1296 switch (cmd_ctx->lsm->domain.type) {
1297 case LTTNG_DOMAIN_KERNEL:
1298 /* Kernel tracer check */
1299 if (kernel_tracer_fd == 0) {
1300 init_kernel_tracer();
1301 if (kernel_tracer_fd == 0) {
1302 ret = LTTCOMM_KERN_NA;
1303 goto error;
1304 }
1305 }
1306
1307 /* Need a session for kernel command */
1308 if (cmd_ctx->lsm->cmd_type != LTTNG_LIST_TRACEPOINTS &&
1309 cmd_ctx->session->kernel_session == NULL) {
1310
1311 ret = create_kernel_session(cmd_ctx->session);
1312 if (ret < 0) {
1313 ret = LTTCOMM_KERN_SESS_FAIL;
1314 goto error;
1315 }
1316
1317 /* Start the kernel consumer daemon */
1318 if (kconsumerd_pid == 0) {
1319 ret = start_kconsumerd();
1320 if (ret < 0) {
1321 goto error;
1322 }
1323 }
1324 }
1325 break;
1326 default:
1327 break;
1328 }
1329
1330 /* Process by command type */
1331 switch (cmd_ctx->lsm->cmd_type) {
1332 case LTTNG_ADD_CONTEXT:
1333 {
1334 struct lttng_kernel_context kctx;
1335
1336 /* Setup lttng message with no payload */
1337 ret = setup_lttng_msg(cmd_ctx, 0);
1338 if (ret < 0) {
1339 goto setup_error;
1340 }
1341
1342 switch (cmd_ctx->lsm->domain.type) {
1343 case LTTNG_DOMAIN_KERNEL:
1344 /* Create Kernel context */
1345 kctx.ctx = cmd_ctx->lsm->u.context.ctx.ctx;
1346 kctx.u.perf_counter.type = cmd_ctx->lsm->u.context.ctx.u.perf_counter.type;
1347 kctx.u.perf_counter.config = cmd_ctx->lsm->u.context.ctx.u.perf_counter.config;
1348 strncpy(kctx.u.perf_counter.name,
1349 cmd_ctx->lsm->u.context.ctx.u.perf_counter.name,
1350 LTTNG_SYMBOL_NAME_LEN);
1351
1352 /* Add kernel context to kernel tracer. See context.c */
1353 ret = add_kernel_context(cmd_ctx->session->kernel_session, &kctx,
1354 cmd_ctx->lsm->u.context.event_name,
1355 cmd_ctx->lsm->u.context.channel_name);
1356 if (ret != LTTCOMM_OK) {
1357 goto error;
1358 }
1359 break;
1360 default:
1361 /* TODO: Userspace tracing */
1362 ret = LTTCOMM_NOT_IMPLEMENTED;
1363 goto error;
1364 }
1365
1366 ret = LTTCOMM_OK;
1367 break;
1368 }
1369 case LTTNG_DISABLE_CHANNEL:
1370 {
1371 struct ltt_kernel_channel *kchan;
1372
1373 /* Setup lttng message with no payload */
1374 ret = setup_lttng_msg(cmd_ctx, 0);
1375 if (ret < 0) {
1376 goto setup_error;
1377 }
1378
1379 switch (cmd_ctx->lsm->domain.type) {
1380 case LTTNG_DOMAIN_KERNEL:
1381 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1382 cmd_ctx->session->kernel_session);
1383 if (kchan == NULL) {
1384 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1385 goto error;
1386 } else if (kchan->enabled == 1) {
1387 ret = kernel_disable_channel(kchan);
1388 if (ret < 0) {
1389 if (ret != EEXIST) {
1390 ret = LTTCOMM_KERN_CHAN_DISABLE_FAIL;
1391 }
1392 goto error;
1393 }
1394 }
1395 kernel_wait_quiescent(kernel_tracer_fd);
1396 break;
1397 default:
1398 /* TODO: Userspace tracing */
1399 ret = LTTCOMM_NOT_IMPLEMENTED;
1400 goto error;
1401 }
1402
1403 ret = LTTCOMM_OK;
1404 break;
1405 }
1406 case LTTNG_DISABLE_EVENT:
1407 {
1408 struct ltt_kernel_channel *kchan;
1409 struct ltt_kernel_event *kevent;
1410
1411 /* Setup lttng message with no payload */
1412 ret = setup_lttng_msg(cmd_ctx, 0);
1413 if (ret < 0) {
1414 goto setup_error;
1415 }
1416
1417 switch (cmd_ctx->lsm->domain.type) {
1418 case LTTNG_DOMAIN_KERNEL:
1419 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1420 cmd_ctx->session->kernel_session);
1421 if (kchan == NULL) {
1422 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1423 goto error;
1424 }
1425
1426 kevent = get_kernel_event_by_name(cmd_ctx->lsm->u.disable.name, kchan);
1427 if (kevent != NULL) {
1428 DBG("Disabling kernel event %s for channel %s.", kevent->event->name,
1429 kchan->channel->name);
1430 ret = kernel_disable_event(kevent);
1431 if (ret < 0) {
1432 ret = LTTCOMM_KERN_ENABLE_FAIL;
1433 goto error;
1434 }
1435 }
1436
1437 kernel_wait_quiescent(kernel_tracer_fd);
1438 break;
1439 default:
1440 /* TODO: Userspace tracing */
1441 ret = LTTCOMM_NOT_IMPLEMENTED;
1442 goto error;
1443 }
1444
1445 ret = LTTCOMM_OK;
1446 break;
1447 }
1448 case LTTNG_DISABLE_ALL_EVENT:
1449 {
1450 struct ltt_kernel_channel *kchan;
1451 struct ltt_kernel_event *kevent;
1452
1453 /* Setup lttng message with no payload */
1454 ret = setup_lttng_msg(cmd_ctx, 0);
1455 if (ret < 0) {
1456 goto setup_error;
1457 }
1458
1459 switch (cmd_ctx->lsm->domain.type) {
1460 case LTTNG_DOMAIN_KERNEL:
1461 DBG("Disabling all enabled kernel events");
1462 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1463 cmd_ctx->session->kernel_session);
1464 if (kchan == NULL) {
1465 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1466 goto error;
1467 }
1468
1469 /* For each event in the kernel session */
1470 cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
1471 DBG("Disabling kernel event %s for channel %s.",
1472 kevent->event->name, kchan->channel->name);
1473 ret = kernel_disable_event(kevent);
1474 if (ret < 0) {
1475 continue;
1476 }
1477 }
1478
1479 /* Quiescent wait after event disable */
1480 kernel_wait_quiescent(kernel_tracer_fd);
1481 break;
1482 default:
1483 /* TODO: Userspace tracing */
1484 ret = LTTCOMM_NOT_IMPLEMENTED;
1485 goto error;
1486 }
1487
1488 ret = LTTCOMM_OK;
1489 break;
1490 }
1491 case LTTNG_ENABLE_CHANNEL:
1492 {
1493 struct ltt_kernel_channel *kchan;
1494
1495 /* Setup lttng message with no payload */
1496 ret = setup_lttng_msg(cmd_ctx, 0);
1497 if (ret < 0) {
1498 goto setup_error;
1499 }
1500
1501 switch (cmd_ctx->lsm->domain.type) {
1502 case LTTNG_DOMAIN_KERNEL:
1503 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.enable.channel_name,
1504 cmd_ctx->session->kernel_session);
1505 if (kchan == NULL) {
1506 /* Channel not found, creating it */
1507 DBG("Creating kernel channel");
1508
1509 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1510 &cmd_ctx->lsm->u.channel.chan, cmd_ctx->session->path);
1511 if (ret < 0) {
1512 ret = LTTCOMM_KERN_CHAN_FAIL;
1513 goto error;
1514 }
1515
1516 /* Notify kernel thread that there is a new channel */
1517 ret = notify_kernel_pollfd();
1518 if (ret < 0) {
1519 ret = LTTCOMM_FATAL;
1520 goto error;
1521 }
1522 } else if (kchan->enabled == 0) {
1523 ret = kernel_enable_channel(kchan);
1524 if (ret < 0) {
1525 if (ret != EEXIST) {
1526 ret = LTTCOMM_KERN_CHAN_ENABLE_FAIL;
1527 }
1528 goto error;
1529 }
1530 }
1531
1532 kernel_wait_quiescent(kernel_tracer_fd);
1533 break;
1534 default:
1535 /* TODO: Userspace tracing */
1536 ret = LTTCOMM_NOT_IMPLEMENTED;
1537 goto error;
1538 }
1539
1540 ret = LTTCOMM_OK;
1541 break;
1542 }
1543 case LTTNG_ENABLE_EVENT:
1544 {
1545 char *channel_name;
1546 struct ltt_kernel_channel *kchan;
1547 struct ltt_kernel_event *kevent;
1548 struct lttng_channel *chan;
1549
1550 /* Setup lttng message with no payload */
1551 ret = setup_lttng_msg(cmd_ctx, 0);
1552 if (ret < 0) {
1553 goto setup_error;
1554 }
1555
1556 channel_name = cmd_ctx->lsm->u.enable.channel_name;
1557
1558 switch (cmd_ctx->lsm->domain.type) {
1559 case LTTNG_DOMAIN_KERNEL:
1560 do {
1561 kchan = get_kernel_channel_by_name(channel_name,
1562 cmd_ctx->session->kernel_session);
1563 if (kchan == NULL) {
1564 DBG("Channel not found. Creating channel %s", channel_name);
1565
1566 chan = init_default_channel(channel_name);
1567 if (chan == NULL) {
1568 ret = LTTCOMM_FATAL;
1569 goto error;
1570 }
1571
1572 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1573 chan, cmd_ctx->session->path);
1574 if (ret < 0) {
1575 ret = LTTCOMM_KERN_CHAN_FAIL;
1576 goto error;
1577 }
1578 }
1579 } while (kchan == NULL);
1580
1581 kevent = get_kernel_event_by_name(cmd_ctx->lsm->u.enable.event.name, kchan);
1582 if (kevent == NULL) {
1583 DBG("Creating kernel event %s for channel %s.",
1584 cmd_ctx->lsm->u.enable.event.name, channel_name);
1585 ret = kernel_create_event(&cmd_ctx->lsm->u.enable.event, kchan);
1586 } else {
1587 DBG("Enabling kernel event %s for channel %s.",
1588 kevent->event->name, channel_name);
1589 ret = kernel_enable_event(kevent);
1590 if (ret == -EEXIST) {
1591 ret = LTTCOMM_KERN_EVENT_EXIST;
1592 goto error;
1593 }
1594 }
1595
1596 if (ret < 0) {
1597 ret = LTTCOMM_KERN_ENABLE_FAIL;
1598 goto error;
1599 }
1600
1601 kernel_wait_quiescent(kernel_tracer_fd);
1602 break;
1603 default:
1604 /* TODO: Userspace tracing */
1605 ret = LTTCOMM_NOT_IMPLEMENTED;
1606 goto error;
1607 }
1608 ret = LTTCOMM_OK;
1609 break;
1610 }
1611 case LTTNG_ENABLE_ALL_EVENT:
1612 {
1613 int size, i;
1614 char *channel_name;
1615 struct ltt_kernel_channel *kchan;
1616 struct ltt_kernel_event *kevent;
1617 struct lttng_event *event_list;
1618 struct lttng_channel *chan;
1619
1620 /* Setup lttng message with no payload */
1621 ret = setup_lttng_msg(cmd_ctx, 0);
1622 if (ret < 0) {
1623 goto setup_error;
1624 }
1625
1626 DBG("Enabling all kernel event");
1627
1628 channel_name = cmd_ctx->lsm->u.enable.channel_name;
1629
1630 switch (cmd_ctx->lsm->domain.type) {
1631 case LTTNG_DOMAIN_KERNEL:
1632 do {
1633 kchan = get_kernel_channel_by_name(channel_name,
1634 cmd_ctx->session->kernel_session);
1635 if (kchan == NULL) {
1636 DBG("Channel not found. Creating channel %s", channel_name);
1637
1638 chan = init_default_channel(channel_name);
1639 if (chan == NULL) {
1640 ret = LTTCOMM_FATAL;
1641 goto error;
1642 }
1643
1644 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1645 chan, cmd_ctx->session->path);
1646 if (ret < 0) {
1647 ret = LTTCOMM_KERN_CHAN_FAIL;
1648 goto error;
1649 }
1650 }
1651 } while (kchan == NULL);
1652
1653 /* For each event in the kernel session */
1654 cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
1655 DBG("Enabling kernel event %s for channel %s.",
1656 kevent->event->name, channel_name);
1657 ret = kernel_enable_event(kevent);
1658 if (ret < 0) {
1659 continue;
1660 }
1661 }
1662
1663 size = kernel_list_events(kernel_tracer_fd, &event_list);
1664 if (size < 0) {
1665 ret = LTTCOMM_KERN_LIST_FAIL;
1666 goto error;
1667 }
1668
1669 for (i = 0; i < size; i++) {
1670 kevent = get_kernel_event_by_name(event_list[i].name, kchan);
1671 if (kevent == NULL) {
1672 /* Default event type for enable all */
1673 event_list[i].type = LTTNG_EVENT_TRACEPOINT;
1674 /* Enable each single tracepoint event */
1675 ret = kernel_create_event(&event_list[i], kchan);
1676 if (ret < 0) {
1677 /* Ignore error here and continue */
1678 }
1679 }
1680 }
1681
1682 free(event_list);
1683
1684 /* Quiescent wait after event enable */
1685 kernel_wait_quiescent(kernel_tracer_fd);
1686 break;
1687 default:
1688 /* TODO: Userspace tracing */
1689 ret = LTTCOMM_NOT_IMPLEMENTED;
1690 goto error;
1691 }
1692
1693 ret = LTTCOMM_OK;
1694 break;
1695 }
1696 case LTTNG_LIST_TRACEPOINTS:
1697 {
1698 struct lttng_event *events;
1699 ssize_t nb_events = 0;
1700
1701 switch (cmd_ctx->lsm->domain.type) {
1702 case LTTNG_DOMAIN_KERNEL:
1703 DBG("Listing kernel events");
1704 nb_events = kernel_list_events(kernel_tracer_fd, &events);
1705 if (nb_events < 0) {
1706 ret = LTTCOMM_KERN_LIST_FAIL;
1707 goto error;
1708 }
1709 break;
1710 default:
1711 /* TODO: Userspace listing */
1712 ret = LTTCOMM_NOT_IMPLEMENTED;
1713 break;
1714 }
1715
1716 /*
1717 * Setup lttng message with payload size set to the event list size in
1718 * bytes and then copy list into the llm payload.
1719 */
1720 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_event) * nb_events);
1721 if (ret < 0) {
1722 free(events);
1723 goto setup_error;
1724 }
1725
1726 /* Copy event list into message payload */
1727 memcpy(cmd_ctx->llm->payload, events,
1728 sizeof(struct lttng_event) * nb_events);
1729
1730 free(events);
1731
1732 ret = LTTCOMM_OK;
1733 break;
1734 }
1735 case LTTNG_START_TRACE:
1736 {
1737 struct ltt_kernel_channel *chan;
1738
1739 /* Setup lttng message with no payload */
1740 ret = setup_lttng_msg(cmd_ctx, 0);
1741 if (ret < 0) {
1742 goto setup_error;
1743 }
1744
1745 /* Kernel tracing */
1746 if (cmd_ctx->session->kernel_session != NULL) {
1747 if (cmd_ctx->session->kernel_session->metadata == NULL) {
1748 DBG("Open kernel metadata");
1749 ret = kernel_open_metadata(cmd_ctx->session->kernel_session,
1750 cmd_ctx->session->path);
1751 if (ret < 0) {
1752 ret = LTTCOMM_KERN_META_FAIL;
1753 goto error;
1754 }
1755 }
1756
1757 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
1758 DBG("Opening kernel metadata stream");
1759 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
1760 ret = kernel_open_metadata_stream(cmd_ctx->session->kernel_session);
1761 if (ret < 0) {
1762 ERR("Kernel create metadata stream failed");
1763 ret = LTTCOMM_KERN_STREAM_FAIL;
1764 goto error;
1765 }
1766 }
1767 }
1768
1769 /* For each channel */
1770 cds_list_for_each_entry(chan,
1771 &cmd_ctx->session->kernel_session->channel_list.head, list) {
1772 if (chan->stream_count == 0) {
1773 ret = kernel_open_channel_stream(chan);
1774 if (ret < 0) {
1775 ERR("Kernel create channel stream failed");
1776 ret = LTTCOMM_KERN_STREAM_FAIL;
1777 goto error;
1778 }
1779 /* Update the stream global counter */
1780 cmd_ctx->session->kernel_session->stream_count_global += ret;
1781 }
1782 }
1783
1784 DBG("Start kernel tracing");
1785 ret = kernel_start_session(cmd_ctx->session->kernel_session);
1786 if (ret < 0) {
1787 ERR("Kernel start session failed");
1788 ret = LTTCOMM_KERN_START_FAIL;
1789 goto error;
1790 }
1791
1792 ret = start_kernel_trace(cmd_ctx->session->kernel_session);
1793 if (ret < 0) {
1794 ret = LTTCOMM_KERN_START_FAIL;
1795 goto error;
1796 }
1797
1798 /* Quiescent wait after starting trace */
1799 kernel_wait_quiescent(kernel_tracer_fd);
1800 }
1801
1802 /* TODO: Start all UST traces */
1803
1804 ret = LTTCOMM_OK;
1805 break;
1806 }
1807 case LTTNG_STOP_TRACE:
1808 {
1809 struct ltt_kernel_channel *chan;
1810 /* Setup lttng message with no payload */
1811 ret = setup_lttng_msg(cmd_ctx, 0);
1812 if (ret < 0) {
1813 goto setup_error;
1814 }
1815
1816 /* Kernel tracer */
1817 if (cmd_ctx->session->kernel_session != NULL) {
1818 DBG("Stop kernel tracing");
1819
1820 ret = kernel_metadata_flush_buffer(cmd_ctx->session->kernel_session->metadata_stream_fd);
1821 if (ret < 0) {
1822 ERR("Kernel metadata flush failed");
1823 }
1824
1825 cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
1826 ret = kernel_flush_buffer(chan);
1827 if (ret < 0) {
1828 ERR("Kernel flush buffer error");
1829 }
1830 }
1831
1832 ret = kernel_stop_session(cmd_ctx->session->kernel_session);
1833 if (ret < 0) {
1834 ERR("Kernel stop session failed");
1835 ret = LTTCOMM_KERN_STOP_FAIL;
1836 goto error;
1837 }
1838
1839 /* Quiescent wait after stopping trace */
1840 kernel_wait_quiescent(kernel_tracer_fd);
1841 }
1842
1843 /* TODO : User-space tracer */
1844
1845 ret = LTTCOMM_OK;
1846 break;
1847 }
1848 case LTTNG_CREATE_SESSION:
1849 {
1850 /* Setup lttng message with no payload */
1851 ret = setup_lttng_msg(cmd_ctx, 0);
1852 if (ret < 0) {
1853 goto setup_error;
1854 }
1855
1856 ret = create_session(cmd_ctx->lsm->session.name, cmd_ctx->lsm->session.path);
1857 if (ret < 0) {
1858 if (ret == -EEXIST) {
1859 ret = LTTCOMM_EXIST_SESS;
1860 } else {
1861 ret = LTTCOMM_FATAL;
1862 }
1863 goto error;
1864 }
1865
1866 ret = LTTCOMM_OK;
1867 break;
1868 }
1869 case LTTNG_DESTROY_SESSION:
1870 {
1871 /* Setup lttng message with no payload */
1872 ret = setup_lttng_msg(cmd_ctx, 0);
1873 if (ret < 0) {
1874 goto setup_error;
1875 }
1876
1877 /* Clean kernel session teardown */
1878 teardown_kernel_session(cmd_ctx->session);
1879
1880 ret = destroy_session(cmd_ctx->lsm->session.name);
1881 if (ret < 0) {
1882 ret = LTTCOMM_FATAL;
1883 goto error;
1884 }
1885
1886 /*
1887 * Must notify the kernel thread here to update it's pollfd in order to
1888 * remove the channel(s)' fd just destroyed.
1889 */
1890 ret = notify_kernel_pollfd();
1891 if (ret < 0) {
1892 ret = LTTCOMM_FATAL;
1893 goto error;
1894 }
1895
1896 ret = LTTCOMM_OK;
1897 break;
1898 }
1899 case LTTNG_LIST_DOMAINS:
1900 {
1901 size_t nb_dom = 0;
1902
1903 if (cmd_ctx->session->kernel_session != NULL) {
1904 nb_dom++;
1905 }
1906
1907 nb_dom += cmd_ctx->session->ust_trace_count;
1908
1909 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_domain) * nb_dom);
1910 if (ret < 0) {
1911 goto setup_error;
1912 }
1913
1914 ((struct lttng_domain *)(cmd_ctx->llm->payload))[0].type =
1915 LTTNG_DOMAIN_KERNEL;
1916
1917 /* TODO: User-space tracer domain support */
1918 ret = LTTCOMM_OK;
1919 break;
1920 }
1921 case LTTNG_LIST_CHANNELS:
1922 {
1923 /*
1924 * TODO: Only kernel channels are listed here. UST listing
1925 * is needed on lttng-ust 2.0 release.
1926 */
1927 size_t nb_chan = 0;
1928 if (cmd_ctx->session->kernel_session != NULL) {
1929 nb_chan += cmd_ctx->session->kernel_session->channel_count;
1930 }
1931
1932 ret = setup_lttng_msg(cmd_ctx,
1933 sizeof(struct lttng_channel) * nb_chan);
1934 if (ret < 0) {
1935 goto setup_error;
1936 }
1937
1938 list_lttng_channels(cmd_ctx->session,
1939 (struct lttng_channel *)(cmd_ctx->llm->payload));
1940
1941 ret = LTTCOMM_OK;
1942 break;
1943 }
1944 case LTTNG_LIST_EVENTS:
1945 {
1946 /*
1947 * TODO: Only kernel events are listed here. UST listing
1948 * is needed on lttng-ust 2.0 release.
1949 */
1950 size_t nb_event = 0;
1951 struct ltt_kernel_channel *kchan = NULL;
1952
1953 if (cmd_ctx->session->kernel_session != NULL) {
1954 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.list.channel_name,
1955 cmd_ctx->session->kernel_session);
1956 if (kchan == NULL) {
1957 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1958 goto error;
1959 }
1960 nb_event += kchan->event_count;
1961 }
1962
1963 ret = setup_lttng_msg(cmd_ctx,
1964 sizeof(struct lttng_event) * nb_event);
1965 if (ret < 0) {
1966 goto setup_error;
1967 }
1968
1969 DBG("Listing events (%ld events)", nb_event);
1970
1971 list_lttng_events(kchan,
1972 (struct lttng_event *)(cmd_ctx->llm->payload));
1973
1974 ret = LTTCOMM_OK;
1975 break;
1976 }
1977 case LTTNG_LIST_SESSIONS:
1978 {
1979 lock_session_list();
1980
1981 if (session_list_ptr->count == 0) {
1982 ret = LTTCOMM_NO_SESSION;
1983 unlock_session_list();
1984 goto error;
1985 }
1986
1987 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) *
1988 session_list_ptr->count);
1989 if (ret < 0) {
1990 unlock_session_list();
1991 goto setup_error;
1992 }
1993
1994 /* Filled the session array */
1995 list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload));
1996
1997 unlock_session_list();
1998
1999 ret = LTTCOMM_OK;
2000 break;
2001 }
2002 default:
2003 /* Undefined command */
2004 ret = setup_lttng_msg(cmd_ctx, 0);
2005 if (ret < 0) {
2006 goto setup_error;
2007 }
2008
2009 ret = LTTCOMM_UND;
2010 break;
2011 }
2012
2013 /* Set return code */
2014 cmd_ctx->llm->ret_code = ret;
2015
2016 if (cmd_ctx->session) {
2017 unlock_session(cmd_ctx->session);
2018 }
2019
2020 return ret;
2021
2022 error:
2023 if (cmd_ctx->llm == NULL) {
2024 DBG("Missing llm structure. Allocating one.");
2025 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
2026 goto setup_error;
2027 }
2028 }
2029 /* Notify client of error */
2030 cmd_ctx->llm->ret_code = ret;
2031
2032 setup_error:
2033 if (cmd_ctx->session) {
2034 unlock_session(cmd_ctx->session);
2035 }
2036 return ret;
2037 }
2038
2039 /*
2040 * This thread manage all clients request using the unix client socket for
2041 * communication.
2042 */
2043 static void *thread_manage_clients(void *data)
2044 {
2045 int sock = 0, ret;
2046 struct command_ctx *cmd_ctx = NULL;
2047 struct pollfd pollfd[2];
2048
2049 DBG("[thread] Manage client started");
2050
2051 ret = lttcomm_listen_unix_sock(client_sock);
2052 if (ret < 0) {
2053 goto error;
2054 }
2055
2056 /* First fd is always the quit pipe */
2057 pollfd[0].fd = thread_quit_pipe[0];
2058
2059 /* Apps socket */
2060 pollfd[1].fd = client_sock;
2061 pollfd[1].events = POLLIN;
2062
2063 /* Notify parent pid that we are ready
2064 * to accept command for client side.
2065 */
2066 if (opt_sig_parent) {
2067 kill(ppid, SIGCHLD);
2068 }
2069
2070 while (1) {
2071 DBG("Accepting client command ...");
2072
2073 /* Inifinite blocking call, waiting for transmission */
2074 ret = poll(pollfd, 2, -1);
2075 if (ret < 0) {
2076 perror("poll client thread");
2077 goto error;
2078 }
2079
2080 /* Thread quit pipe has been closed. Killing thread. */
2081 if (pollfd[0].revents == POLLNVAL) {
2082 goto error;
2083 } else if (pollfd[1].revents == POLLERR) {
2084 ERR("Client socket poll error");
2085 goto error;
2086 }
2087
2088 sock = lttcomm_accept_unix_sock(client_sock);
2089 if (sock < 0) {
2090 goto error;
2091 }
2092
2093 /* Allocate context command to process the client request */
2094 cmd_ctx = malloc(sizeof(struct command_ctx));
2095
2096 /* Allocate data buffer for reception */
2097 cmd_ctx->lsm = malloc(sizeof(struct lttcomm_session_msg));
2098 cmd_ctx->llm = NULL;
2099 cmd_ctx->session = NULL;
2100
2101 /*
2102 * Data is received from the lttng client. The struct
2103 * lttcomm_session_msg (lsm) contains the command and data request of
2104 * the client.
2105 */
2106 DBG("Receiving data from client ...");
2107 ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm, sizeof(struct lttcomm_session_msg));
2108 if (ret <= 0) {
2109 continue;
2110 }
2111
2112 // TODO: Validate cmd_ctx including sanity check for security purpose.
2113
2114 /*
2115 * This function dispatch the work to the kernel or userspace tracer
2116 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2117 * informations for the client. The command context struct contains
2118 * everything this function may needs.
2119 */
2120 ret = process_client_msg(cmd_ctx);
2121 if (ret < 0) {
2122 /* TODO: Inform client somehow of the fatal error. At this point,
2123 * ret < 0 means that a malloc failed (ENOMEM). */
2124 /* Error detected but still accept command */
2125 clean_command_ctx(&cmd_ctx);
2126 continue;
2127 }
2128
2129 DBG("Sending response (size: %d, retcode: %d)",
2130 cmd_ctx->lttng_msg_size, cmd_ctx->llm->ret_code);
2131 ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
2132 if (ret < 0) {
2133 ERR("Failed to send data back to client");
2134 }
2135
2136 clean_command_ctx(&cmd_ctx);
2137
2138 /* End of transmission */
2139 close(sock);
2140 }
2141
2142 error:
2143 DBG("Client thread dying");
2144 if (client_sock) {
2145 close(client_sock);
2146 }
2147 if (sock) {
2148 close(sock);
2149 }
2150
2151 unlink(client_unix_sock_path);
2152
2153 clean_command_ctx(&cmd_ctx);
2154 return NULL;
2155 }
2156
2157
2158 /*
2159 * usage function on stderr
2160 */
2161 static void usage(void)
2162 {
2163 fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
2164 fprintf(stderr, " -h, --help Display this usage.\n");
2165 fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n");
2166 fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n");
2167 fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
2168 fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
2169 fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
2170 fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
2171 fprintf(stderr, " -V, --version Show version number.\n");
2172 fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
2173 fprintf(stderr, " -q, --quiet No output at all.\n");
2174 fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
2175 }
2176
2177 /*
2178 * daemon argument parsing
2179 */
2180 static int parse_args(int argc, char **argv)
2181 {
2182 int c;
2183
2184 static struct option long_options[] = {
2185 { "client-sock", 1, 0, 'c' },
2186 { "apps-sock", 1, 0, 'a' },
2187 { "kconsumerd-cmd-sock", 1, 0, 0 },
2188 { "kconsumerd-err-sock", 1, 0, 0 },
2189 { "daemonize", 0, 0, 'd' },
2190 { "sig-parent", 0, 0, 'S' },
2191 { "help", 0, 0, 'h' },
2192 { "group", 1, 0, 'g' },
2193 { "version", 0, 0, 'V' },
2194 { "quiet", 0, 0, 'q' },
2195 { "verbose", 0, 0, 'v' },
2196 { NULL, 0, 0, 0 }
2197 };
2198
2199 while (1) {
2200 int option_index = 0;
2201 c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:E:C:", long_options, &option_index);
2202 if (c == -1) {
2203 break;
2204 }
2205
2206 switch (c) {
2207 case 0:
2208 fprintf(stderr, "option %s", long_options[option_index].name);
2209 if (optarg) {
2210 fprintf(stderr, " with arg %s\n", optarg);
2211 }
2212 break;
2213 case 'c':
2214 snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
2215 break;
2216 case 'a':
2217 snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
2218 break;
2219 case 'd':
2220 opt_daemon = 1;
2221 break;
2222 case 'g':
2223 opt_tracing_group = strdup(optarg);
2224 break;
2225 case 'h':
2226 usage();
2227 exit(EXIT_FAILURE);
2228 case 'V':
2229 fprintf(stdout, "%s\n", VERSION);
2230 exit(EXIT_SUCCESS);
2231 case 'S':
2232 opt_sig_parent = 1;
2233 break;
2234 case 'E':
2235 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, "%s", optarg);
2236 break;
2237 case 'C':
2238 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, "%s", optarg);
2239 break;
2240 case 'q':
2241 opt_quiet = 1;
2242 break;
2243 case 'v':
2244 /* Verbose level can increase using multiple -v */
2245 opt_verbose += 1;
2246 break;
2247 default:
2248 /* Unknown option or other error.
2249 * Error is printed by getopt, just return */
2250 return -1;
2251 }
2252 }
2253
2254 return 0;
2255 }
2256
2257 /*
2258 * Creates the two needed socket by the daemon.
2259 * apps_sock - The communication socket for all UST apps.
2260 * client_sock - The communication of the cli tool (lttng).
2261 */
2262 static int init_daemon_socket()
2263 {
2264 int ret = 0;
2265 mode_t old_umask;
2266
2267 old_umask = umask(0);
2268
2269 /* Create client tool unix socket */
2270 client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
2271 if (client_sock < 0) {
2272 ERR("Create unix sock failed: %s", client_unix_sock_path);
2273 ret = -1;
2274 goto end;
2275 }
2276
2277 /* File permission MUST be 660 */
2278 ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2279 if (ret < 0) {
2280 ERR("Set file permissions failed: %s", client_unix_sock_path);
2281 perror("chmod");
2282 goto end;
2283 }
2284
2285 /* Create the application unix socket */
2286 apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
2287 if (apps_sock < 0) {
2288 ERR("Create unix sock failed: %s", apps_unix_sock_path);
2289 ret = -1;
2290 goto end;
2291 }
2292
2293 /* File permission MUST be 666 */
2294 ret = chmod(apps_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
2295 if (ret < 0) {
2296 ERR("Set file permissions failed: %s", apps_unix_sock_path);
2297 perror("chmod");
2298 goto end;
2299 }
2300
2301 end:
2302 umask(old_umask);
2303 return ret;
2304 }
2305
2306 /*
2307 * Check if the global socket is available. If yes, error is returned.
2308 */
2309 static int check_existing_daemon()
2310 {
2311 int ret;
2312
2313 ret = access(client_unix_sock_path, F_OK);
2314 if (ret == 0) {
2315 ret = access(apps_unix_sock_path, F_OK);
2316 }
2317
2318 return ret;
2319 }
2320
2321 /*
2322 * Set the tracing group gid onto the client socket.
2323 *
2324 * Race window between mkdir and chown is OK because we are going from more
2325 * permissive (root.root) to les permissive (root.tracing).
2326 */
2327 static int set_permissions(void)
2328 {
2329 int ret;
2330 struct group *grp;
2331
2332 /* Decide which group name to use */
2333 (opt_tracing_group != NULL) ?
2334 (grp = getgrnam(opt_tracing_group)) :
2335 (grp = getgrnam(default_tracing_group));
2336
2337 if (grp == NULL) {
2338 if (is_root) {
2339 WARN("No tracing group detected");
2340 ret = 0;
2341 } else {
2342 ERR("Missing tracing group. Aborting execution.");
2343 ret = -1;
2344 }
2345 goto end;
2346 }
2347
2348 /* Set lttng run dir */
2349 ret = chown(LTTNG_RUNDIR, 0, grp->gr_gid);
2350 if (ret < 0) {
2351 ERR("Unable to set group on " LTTNG_RUNDIR);
2352 perror("chown");
2353 }
2354
2355 /* lttng client socket path */
2356 ret = chown(client_unix_sock_path, 0, grp->gr_gid);
2357 if (ret < 0) {
2358 ERR("Unable to set group on %s", client_unix_sock_path);
2359 perror("chown");
2360 }
2361
2362 /* kconsumerd error socket path */
2363 ret = chown(kconsumerd_err_unix_sock_path, 0, grp->gr_gid);
2364 if (ret < 0) {
2365 ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path);
2366 perror("chown");
2367 }
2368
2369 DBG("All permissions are set");
2370
2371 end:
2372 return ret;
2373 }
2374
2375 /*
2376 * Create the pipe used to wake up the kernel thread.
2377 */
2378 static int create_kernel_poll_pipe(void)
2379 {
2380 return pipe2(kernel_poll_pipe, O_CLOEXEC);
2381 }
2382
2383 /*
2384 * Create the lttng run directory needed for all global sockets and pipe.
2385 */
2386 static int create_lttng_rundir(void)
2387 {
2388 int ret;
2389
2390 ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
2391 if (ret < 0) {
2392 if (errno != EEXIST) {
2393 ERR("Unable to create " LTTNG_RUNDIR);
2394 goto error;
2395 } else {
2396 ret = 0;
2397 }
2398 }
2399
2400 error:
2401 return ret;
2402 }
2403
2404 /*
2405 * Setup sockets and directory needed by the kconsumerd communication with the
2406 * session daemon.
2407 */
2408 static int set_kconsumerd_sockets(void)
2409 {
2410 int ret;
2411
2412 if (strlen(kconsumerd_err_unix_sock_path) == 0) {
2413 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, KCONSUMERD_ERR_SOCK_PATH);
2414 }
2415
2416 if (strlen(kconsumerd_cmd_unix_sock_path) == 0) {
2417 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, KCONSUMERD_CMD_SOCK_PATH);
2418 }
2419
2420 ret = mkdir(KCONSUMERD_PATH, S_IRWXU | S_IRWXG);
2421 if (ret < 0) {
2422 if (errno != EEXIST) {
2423 ERR("Failed to create " KCONSUMERD_PATH);
2424 goto error;
2425 }
2426 ret = 0;
2427 }
2428
2429 /* Create the kconsumerd error unix socket */
2430 kconsumerd_err_sock = lttcomm_create_unix_sock(kconsumerd_err_unix_sock_path);
2431 if (kconsumerd_err_sock < 0) {
2432 ERR("Create unix sock failed: %s", kconsumerd_err_unix_sock_path);
2433 ret = -1;
2434 goto error;
2435 }
2436
2437 /* File permission MUST be 660 */
2438 ret = chmod(kconsumerd_err_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2439 if (ret < 0) {
2440 ERR("Set file permissions failed: %s", kconsumerd_err_unix_sock_path);
2441 perror("chmod");
2442 goto error;
2443 }
2444
2445 error:
2446 return ret;
2447 }
2448
2449 /*
2450 * Signal handler for the daemon
2451 */
2452 static void sighandler(int sig)
2453 {
2454 switch (sig) {
2455 case SIGPIPE:
2456 DBG("SIGPIPE catched");
2457 return;
2458 case SIGINT:
2459 DBG("SIGINT catched");
2460 cleanup();
2461 break;
2462 case SIGTERM:
2463 DBG("SIGTERM catched");
2464 cleanup();
2465 break;
2466 default:
2467 break;
2468 }
2469
2470 exit(EXIT_SUCCESS);
2471 }
2472
2473 /*
2474 * Setup signal handler for :
2475 * SIGINT, SIGTERM, SIGPIPE
2476 */
2477 static int set_signal_handler(void)
2478 {
2479 int ret = 0;
2480 struct sigaction sa;
2481 sigset_t sigset;
2482
2483 if ((ret = sigemptyset(&sigset)) < 0) {
2484 perror("sigemptyset");
2485 return ret;
2486 }
2487
2488 sa.sa_handler = sighandler;
2489 sa.sa_mask = sigset;
2490 sa.sa_flags = 0;
2491 if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
2492 perror("sigaction");
2493 return ret;
2494 }
2495
2496 if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
2497 perror("sigaction");
2498 return ret;
2499 }
2500
2501 if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
2502 perror("sigaction");
2503 return ret;
2504 }
2505
2506 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
2507
2508 return ret;
2509 }
2510
2511 /*
2512 * Set open files limit to unlimited. This daemon can open a large number of
2513 * file descriptors in order to consumer multiple kernel traces.
2514 */
2515 static void set_ulimit(void)
2516 {
2517 int ret;
2518 struct rlimit lim;
2519
2520 /* The kernel does not allowed an infinite limit for open files */
2521 lim.rlim_cur = 65535;
2522 lim.rlim_max = 65535;
2523
2524 ret = setrlimit(RLIMIT_NOFILE, &lim);
2525 if (ret < 0) {
2526 perror("failed to set open files limit");
2527 }
2528 }
2529
2530 /*
2531 * main
2532 */
2533 int main(int argc, char **argv)
2534 {
2535 int ret = 0;
2536 void *status;
2537 const char *home_path;
2538
2539 /* Create thread quit pipe */
2540 if (init_thread_quit_pipe() < 0) {
2541 goto exit;
2542 }
2543
2544 /* Parse arguments */
2545 progname = argv[0];
2546 if ((ret = parse_args(argc, argv) < 0)) {
2547 goto exit;
2548 }
2549
2550 /* Daemonize */
2551 if (opt_daemon) {
2552 ret = daemon(0, 0);
2553 if (ret < 0) {
2554 perror("daemon");
2555 goto exit;
2556 }
2557 }
2558
2559 /* Check if daemon is UID = 0 */
2560 is_root = !getuid();
2561
2562 if (is_root) {
2563 ret = create_lttng_rundir();
2564 if (ret < 0) {
2565 goto exit;
2566 }
2567
2568 if (strlen(apps_unix_sock_path) == 0) {
2569 snprintf(apps_unix_sock_path, PATH_MAX,
2570 DEFAULT_GLOBAL_APPS_UNIX_SOCK);
2571 }
2572
2573 if (strlen(client_unix_sock_path) == 0) {
2574 snprintf(client_unix_sock_path, PATH_MAX,
2575 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
2576 }
2577 } else {
2578 home_path = get_home_dir();
2579 if (home_path == NULL) {
2580 /* TODO: Add --socket PATH option */
2581 ERR("Can't get HOME directory for sockets creation.");
2582 goto exit;
2583 }
2584
2585 if (strlen(apps_unix_sock_path) == 0) {
2586 snprintf(apps_unix_sock_path, PATH_MAX,
2587 DEFAULT_HOME_APPS_UNIX_SOCK, home_path);
2588 }
2589
2590 /* Set the cli tool unix socket path */
2591 if (strlen(client_unix_sock_path) == 0) {
2592 snprintf(client_unix_sock_path, PATH_MAX,
2593 DEFAULT_HOME_CLIENT_UNIX_SOCK, home_path);
2594 }
2595 }
2596
2597 DBG("Client socket path %s", client_unix_sock_path);
2598 DBG("Application socket path %s", apps_unix_sock_path);
2599
2600 /*
2601 * See if daemon already exist. If any of the two socket needed by the
2602 * daemon are present, this test fails. However, if the daemon is killed
2603 * with a SIGKILL, those unix socket must be unlinked by hand.
2604 */
2605 if ((ret = check_existing_daemon()) == 0) {
2606 ERR("Already running daemon.\n");
2607 /*
2608 * We do not goto error because we must not cleanup() because a daemon
2609 * is already running.
2610 */
2611 goto exit;
2612 }
2613
2614 /* After this point, we can safely call cleanup() so goto error is used */
2615
2616 /*
2617 * These actions must be executed as root. We do that *after* setting up
2618 * the sockets path because we MUST make the check for another daemon using
2619 * those paths *before* trying to set the kernel consumer sockets and init
2620 * kernel tracer.
2621 */
2622 if (is_root) {
2623 ret = set_kconsumerd_sockets();
2624 if (ret < 0) {
2625 goto error;
2626 }
2627
2628 /* Setup kernel tracer */
2629 init_kernel_tracer();
2630
2631 /* Set ulimit for open files */
2632 set_ulimit();
2633 }
2634
2635 if (set_signal_handler() < 0) {
2636 goto error;
2637 }
2638
2639 /* Setup the needed unix socket */
2640 if (init_daemon_socket() < 0) {
2641 goto error;
2642 }
2643
2644 /* Set credentials to socket */
2645 if (is_root && (set_permissions() < 0)) {
2646 goto error;
2647 }
2648
2649 /* Get parent pid if -S, --sig-parent is specified. */
2650 if (opt_sig_parent) {
2651 ppid = getppid();
2652 }
2653
2654 /* Setup the kernel pipe for waking up the kernel thread */
2655 if (create_kernel_poll_pipe() < 0) {
2656 goto error;
2657 }
2658
2659 /*
2660 * Get session list pointer. This pointer MUST NOT be free().
2661 * This list is statically declared in session.c
2662 */
2663 session_list_ptr = get_session_list();
2664
2665 while (1) {
2666 /* Create thread to manage the client socket */
2667 ret = pthread_create(&client_thread, NULL, thread_manage_clients, (void *) NULL);
2668 if (ret != 0) {
2669 perror("pthread_create");
2670 goto error;
2671 }
2672
2673 /* Create thread to manage application socket */
2674 ret = pthread_create(&apps_thread, NULL, thread_manage_apps, (void *) NULL);
2675 if (ret != 0) {
2676 perror("pthread_create");
2677 goto error;
2678 }
2679
2680 /* Create kernel thread to manage kernel event */
2681 ret = pthread_create(&kernel_thread, NULL, thread_manage_kernel, (void *) NULL);
2682 if (ret != 0) {
2683 perror("pthread_create");
2684 goto error;
2685 }
2686
2687 ret = pthread_join(client_thread, &status);
2688 if (ret != 0) {
2689 perror("pthread_join");
2690 goto error;
2691 }
2692 }
2693
2694 cleanup();
2695 exit(EXIT_SUCCESS);
2696
2697 error:
2698 cleanup();
2699
2700 exit:
2701 exit(EXIT_FAILURE);
2702 }
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